This invention relates to an information recording medium, and more particularly, to a heat-mode information recording medium as well as a recording method.
Heat-mode information recording media have the advantage that they are not worn or degraded because they are not in contact with writing and reading heads. Active research and development work has been focused to a variety of heat-mode recording media. The heat-mode information recording media are generally classified into two types, pit forming type and phase transition type.
In the information recording medium of phase transition type, recording light, typically a laser beam is directed to the recording layer to induce amorphous-crystalline phase transition at the exposed spot, thereby recording information thereat. The recorded information can be read out by directing reading light to the recorded spot to detect a variation in reflectance or the like.
Most recording media utilizing such phase transition have recording layers of tellurium (Te) based materials, for example, As-Se-Te. Because tellurium-based materials are toxic to the human body, the recent research is to develop substitute materials. As far as the inventors know, no report has been presented as to the discovery of a useful recording medium using a less toxic material instead of the tellurium-based materials.